Schizophrenia patients show regional alterations in βI-tubulin expression
MedWire News: Results from a US study show that patients with schizophrenia have regional alterations in the expression of an isoform of the cytoskeleton protein β-tubulin, which is a major component of axons, dendrites, and dendritic spines.
Writing in the journal Schizophrenia Research, Robert McCullumsmith (University of Alabama at Birmingham School of Medicine) and colleagues explain: "The cytoskeleton, a dynamic composition of structural proteins, contributes to the function and morphology of dendrites, spines, synapses, and a myriad of biological processes including cell division and chemotaxis."
They add: "Growing evidence for cytoskeletal disturbances in schizophrenia and the notion that specific isoforms of β-tubulin have unique roles in cellular function suggest that there may be isoform-specific abnormalities of β-tubulin expression in schizophrenia."
To investigate, the team studied 110 postmortem brain tissue samples from the dorsolateral prefrontal cortex (DLPFC), the anterior cingulate cortex (ACC), the hippocampus (HC), and the superior temporal gyrus (STG) of elderly patients with schizophrenia and 103 from similarly aged mentally healthy individuals.
Western blot analysis was used to compare regional expression of the β-tubulin isoforms βI, βII, βIII, and βIV between the two groups.
The researchers found that ACC tissue samples from schizophrenia patients showed a significant decrease in βI expression compared with those from controls, with no significant differences in βII, βIII, and βIV expression.
By contrast, DLPFC tissue samples from schizophrenia patients showed a significant increase in βI expression compared with those from controls, but, again, with no significant differences in βII, βIII, and βIV expression.
To determine if these alterations in βI isoform expression were region specific, the team examined expression in the HC and STG, but found no significant difference in βI expression between the groups in either region.
There were no significant associations between expression of the β-tubulin isoforms and age, gender, tissue pH, or postmortem interval, the researchers note.
McCullumsmith and colleagues conclude: "Our data support a growing body of evidence suggesting abnormalities of the cytoskeleton in schizophrenia."
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By Mark Cowen